1.1 Description of the components
The list of sensors and actuators of the unit is divided into several categories. The following components
make up part of the unit assembly.
Actuators
Compressors
• In cold only units they are responsible for generating cold.
• In pump units they are responsible for generating cold and heat.
• According to the setup of the SW4 it is possible to choose from between 1
compressor ‑ 1 circuit or 2 compressors (tandem) ‑ 1 circuit.
Indoor fan It is used to circulate the air through the indoor coil and conduct it to the supply.
Outdoor fans
• They are used to circulate the air through the outdoor coil.
• According to the setup of the SW the operation of the outdoor fan varies in
cool mode in accordance with the outside temperature.
4-way valve
(pump)
It is used to switch the operating cycle of the unit (cool ‑ heat).
Temperature
probes
Suction The temperature probe is placed on the suction of the compressor.
Outdoors The temperature probe is placed outdoors.
Liquid The temperature probe is placed on the outdoor coil liquid tube.
Discharge The temperature probe is placed on the compressor discharge.
Supply The temperature probe is placed on the air supply.
Return
The temperature probe is placed on the air return with the economiser acces‐
sory.
Water
The temperature probe is placed on the water inlet of the hot water coil acces‐
sory.
Enthalpy
probes
Outdoors
Enthalpy probes are placed on the outside of the economiser accessory (only
on Roof top).
Return
Enthalpy probes are placed on the return of the economiser accessory (only on
Roof top).
Protections
Fan thermal switch It indicates that the indoor fan protection has come into operation.
High-pressure switch
It indicates that the unit high pressure is outside the limits or the protection of
the outdoor fan or the compressor module has been activated.
Low-pressure switch It indicates that the unit low pressure is outside the limits.
Accessories
Compressor 2 and pres‐
ence sensor
It adds a presence input and an extra compressor stage to the unit.
Compressor 3 It adds an extra compressor stage to the unit.
Electric resistors (*) They are used to support the heat generation (up to 4 stages).
Gas burners (*) Heat generation using gas (up to 4 stages).
Hot water coil (*) It is used to support the heat generation (up to 4 stages).
Economiser, return fan and
air quality probe
• It allows for cold to be generated by modulating the outdoor air inlet damper
and the renewal of indoor air. The fan increases the capacity of air exhaust
from the room.
• It enables air renewal in accordance with the values of the air quality probe.
Motorised damper It enables air renewal to be fixed.
Smoke and high tempera‐
ture detector
It detects the presence of smoke in the room or high supply temperature.
Dirty filter detector It detects whether the filters must be changed.
(*) Together they are incompatible. It is only possible to have one type of support heat generator.
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Components
1.1 Description of the components
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